A printer body (ink jet printer body) is provided with an ink jet head and ejects ink droplets by pressurizing ink. In the related art, the ink jet head is provided with a driver integrated circuit (IC) for driving ejection, and a cover is provided on an outside of the driver IC, the cover being adapted to release heat from the driver IC as a heat sink. Furthermore, a print wiring substrate on which a peripheral circuit is mounted is provided for driving the driver IC. It is necessary to prevent ink or ink mist leaked or scattered from a boundary surface between components, such as the head body, a mask plate, and the cover, from adhering to the print wiring substrate. Thus, penetration of ink is prevented by performing sealing by pouring a sealing material, such as adhesive, into gaps at the boundary surface between the components.
However, since there are large boundary surfaces between the components dictated by the complex shape of each component, when connecting a pipe of an ink circulation system to an ink tube of the ink jet head, ink may be spilled from the pipe. The spilled ink enters an inside of the cover and adheres to the print wiring substrate.